Newbie Solar Project - small

smasonsmason Registered Users Posts: 1
Hello forum members,

So here is what I'm thinking of doing, I'd like to install a small solar system sort of as a trial run on my property and if successful then I'll move to a larger system later. So here is a little background; I have two meters on my property, one is for the house (residential) the other meter is for General Purpose which is tied to a detached garage. At the detached garage I have a 200amp panel, which then feeds a 100amp subpanel to the barn. The Barn is where I would like to install the solar panel(s) and wiring due to the panels would get vastly more sun exposure than the garage. On a monthly basis the power use is around 60-70kwh per month. Basically a dusk to dawn light is run and that's about it.

There are two Solar wattage kits I'm looking at and both are from the same manufacture.

Westinghouse Solor - 235watt kit or 940watt kit. These come with the enphase microinverters and the racking/mounting is built into these units which to me sounds like a good idea.

My understanding is the 235kit should give me around 30kWh per month and the 930 around 120kWh per month.

I'm curious if anyone has any exposure with these panels/kits. This site doesn't seem to have much information on whether they are good/bad. The internet has a vew youtube vids but, mainly you are not going see someone bad mouthing a product they just shelled out a few grand for. Anyway so far haven't found too many reviews on them.

Other requirements for this system:

Looking for a Grid Tie Systesm
I do not want/need a battery backup system
Also would like the system to be simple




  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    Re: Newbie Solar Project - small

    You have to check with your utility and make sure they support GT solar and have a net metering plan (or similar) that is cost effective for you.

    In California, we have to switch to Time of Use metering--For small systems (relative to total power usage), it can actually raise the home owner's bill (base rate, we pay ~$0.09 for off peak and $0.27 per kWH for peak power--If you use a lot of power, such as AC, during weekday afternoons, it can cause the bill to increase significantly).

    Anyway, using PV Watts for a 1kW (1,000 watt) fixed array tilted to latitude, near Richmond Virginia:
    "Station Identification"
    "Lat (deg N):", 37.50
    "Long (deg W):", 77.33
    "Elev (m): ", 50
    "PV System Specifications"
    "DC Rating:"," 1.0 kW"
    "DC to AC Derate Factor:"," 0.770"
    "AC Rating:"," 0.8 kW"
    "Array Type: Fixed Tilt"
    "Array Tilt:"," 37.5"
    "Array Azimuth:","180.0"

    "Energy Specifications"
    "Cost of Electricity:"," 8.0 cents/kWh"

    "Month", "Solar Radiation (kWh/m^2/day)", "AC Energy (kWh)", "Energy Value ($)"
    1, 3.99, 96, 7.68
    2, 4.37, 94, 7.52
    3, 4.96, 115, 9.20
    4, 5.32, 114, 9.12
    5, 5.49, 120, 9.60
    6, 5.54, 113, 9.04
    7, 5.55, 116, 9.28
    8, 5.31, 113, 9.04
    9, 5.30, 110, 8.80
    10, 4.65, 103, 8.24
    11, 3.95, 89, 7.12
    12, 3.51, 83, 6.64
    "Year", 4.83, 1266, 101.28

    So, for 1,000 watt array, you are looking at ~83 to 120 kWH per month (long term average).

    Check pricing of components as well as the kit. There is not that much in the way of specialized parts required for grid tied installations. So don't over pay for the kit.

    As always--I would suggest that you look at your power usage and make sure you have done as much conservation as possible (insulation, double pane windows, energy star appliances, efficient A/C, heat pump instead of resistance heat/hot water, gas stove, etc.). It is almost alway less expensive and a better investment than a solar PV system.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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